summaryrefslogtreecommitdiffstats
path: root/src/mesa/drivers/windows/gdi/wgl.c
blob: bf4ca9c908f0a330a280370c93da27f90bdd38cd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707

/*
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

/*
 * File name 	: wgl.c
 * WGL stuff. Added by Oleg Letsinsky, ajl@ultersys.ru
 * Some things originated from the 3Dfx WGL functions
 */

/* 
 * This file contains the implementation of the wgl* functions for
 * Mesa on Windows.  Since these functions are provided by Windows in
 * GDI/OpenGL, we must supply our versions that work with Mesa here.
 */


/* We're essentially building part of GDI here, so define this so that
 * we get the right export linkage. */
#ifdef __MINGW32__

#include <stdarg.h>
#include <windef.h>
#include <wincon.h>
#include <winbase.h>

#  if defined(BUILD_GL32)
#    define WINGDIAPI __declspec(dllexport)	
#  else
#    define __W32API_USE_DLLIMPORT__
#  endif

#include <wingdi.h>
#include "GL/mesa_wgl.h"
#include <stdlib.h>

#else

#define _GDI32_
#include <windows.h>

#endif
#include "main/config.h"
#include "glapi/glapi.h"
#include "GL/wmesa.h"   /* protos for wmesa* functions */

/*
 * Pixel Format Descriptors
 */

/* Extend the PFD to include DB flag */
struct __pixelformat__
{
    PIXELFORMATDESCRIPTOR pfd;
    GLboolean doubleBuffered;
};



/* These are the PFD's supported by this driver. */
struct __pixelformat__	pfd[] =
{
#if 0 
    /* Double Buffer, alpha */
    {	
	{	
	    sizeof(PIXELFORMATDESCRIPTOR),	1,
	    PFD_DRAW_TO_WINDOW|PFD_SUPPORT_OPENGL|
	    PFD_GENERIC_FORMAT|PFD_DOUBLEBUFFER|PFD_SWAP_COPY,
	    PFD_TYPE_RGBA,
	    24,	
	    8, 0,	
	    8, 8,	
	    8, 16,	
	    8, 24,
	    0, 0, 0, 0, 0,	
	    DEFAULT_SOFTWARE_DEPTH_BITS,	8,	
	    0, 0, 0,	
	    0, 0, 0 
	},
        GL_TRUE
    },
    /* Single Buffer, alpha */
    {	
	{	
	    sizeof(PIXELFORMATDESCRIPTOR),	1,
	    PFD_DRAW_TO_WINDOW|PFD_SUPPORT_OPENGL|
	    PFD_GENERIC_FORMAT,
	    PFD_TYPE_RGBA,
	    24,	
	    8, 0,	
	    8, 8,	
	    8, 16,	
	    8, 24,
	    0, 0, 0, 0,	0,	
	    DEFAULT_SOFTWARE_DEPTH_BITS,	8,	
	    0, 0, 0,	
	    0, 0, 0
	},
        GL_FALSE
    },
#endif 
    /* Double Buffer, no alpha */
    {	
	{	
	    sizeof(PIXELFORMATDESCRIPTOR),	1,
	    PFD_DRAW_TO_WINDOW|PFD_SUPPORT_OPENGL|
	    PFD_GENERIC_FORMAT|PFD_DOUBLEBUFFER|PFD_SWAP_COPY,
	    PFD_TYPE_RGBA,
	    24,	
	    8, 0,
	    8, 8,
	    8, 16,
	    0, 0,
	    0, 0, 0, 0,	0,
	    DEFAULT_SOFTWARE_DEPTH_BITS,	8,	
	    0, 0, 0, 
	    0, 0, 0 
	},
        GL_TRUE
    },
    /* Single Buffer, no alpha */
    {	
	{
	    sizeof(PIXELFORMATDESCRIPTOR),	1,
	    PFD_DRAW_TO_WINDOW|PFD_SUPPORT_OPENGL|
	    PFD_GENERIC_FORMAT,
	    PFD_TYPE_RGBA,
	    24,	
	    8, 0,
	    8, 8,
	    8, 16,
	    0, 0,
	    0, 0, 0, 0,	0,
	    DEFAULT_SOFTWARE_DEPTH_BITS,	8,	
	    0, 0, 0,
	    0, 0, 0 
	},
        GL_FALSE
    },
};

int npfd = sizeof(pfd) / sizeof(pfd[0]);


/*
 * Contexts
 */

typedef struct {
    WMesaContext ctx;
} MesaWglCtx;

#define MESAWGL_CTX_MAX_COUNT 20

static MesaWglCtx wgl_ctx[MESAWGL_CTX_MAX_COUNT];

static unsigned ctx_count = 0;
static int ctx_current = -1;
static unsigned curPFD = 0;

static HDC CurrentHDC = 0;


WINGDIAPI HGLRC GLAPIENTRY wglCreateContext(HDC hdc)
{
    int i = 0;
    if (!ctx_count) {
	for(i=0;i<MESAWGL_CTX_MAX_COUNT;i++) {
	    wgl_ctx[i].ctx = NULL;
	}
    }
    for( i = 0; i < MESAWGL_CTX_MAX_COUNT; i++ ) {
        if ( wgl_ctx[i].ctx == NULL ) {
            wgl_ctx[i].ctx = 
		WMesaCreateContext(hdc, NULL, (GLboolean)GL_TRUE,
				   (GLboolean) (pfd[curPFD-1].doubleBuffered ?
                                   GL_TRUE : GL_FALSE), 
				   (GLboolean)(pfd[curPFD-1].pfd.cAlphaBits ? 
				   GL_TRUE : GL_FALSE) );
            if (wgl_ctx[i].ctx == NULL)
                break;
            ctx_count++;
            return ((HGLRC)wgl_ctx[i].ctx);
        }
    }
    SetLastError(0);
    return(NULL);
}

WINGDIAPI BOOL GLAPIENTRY wglDeleteContext(HGLRC hglrc)
{
    int i;
    for ( i = 0; i < MESAWGL_CTX_MAX_COUNT; i++ ) {
    	if ( wgl_ctx[i].ctx == (WMesaContext) hglrc ){
            WMesaMakeCurrent((WMesaContext) hglrc, NULL);
            WMesaDestroyContext(wgl_ctx[i].ctx);
            wgl_ctx[i].ctx = NULL;
            ctx_count--;
            return(TRUE);
    	}
    }
    SetLastError(0);
    return(FALSE);
}

WINGDIAPI HGLRC GLAPIENTRY wglGetCurrentContext(VOID)
{
    if (ctx_current < 0)
	return 0;
    else
	return (HGLRC) wgl_ctx[ctx_current].ctx;
}

WINGDIAPI HDC GLAPIENTRY wglGetCurrentDC(VOID)
{
    return CurrentHDC;
}

WINGDIAPI BOOL GLAPIENTRY wglMakeCurrent(HDC hdc, HGLRC hglrc)
{
    int i;
    
    CurrentHDC = hdc;

    if (!hdc || !hglrc) {
	WMesaMakeCurrent(NULL, NULL);
	ctx_current = -1;
	return TRUE;
    }
    
    for ( i = 0; i < MESAWGL_CTX_MAX_COUNT; i++ ) {
	if ( wgl_ctx[i].ctx == (WMesaContext) hglrc ) {
	    WMesaMakeCurrent( (WMesaContext) hglrc, hdc );
	    ctx_current = i;
	    return TRUE;
	}
    }
    return FALSE;
}


WINGDIAPI int GLAPIENTRY wglChoosePixelFormat(HDC hdc,
					      CONST 
					      PIXELFORMATDESCRIPTOR *ppfd)
{
    int		i,best = -1,bestdelta = 0x7FFFFFFF,delta;
    (void) hdc;
    
    if(ppfd->nSize != sizeof(PIXELFORMATDESCRIPTOR) || ppfd->nVersion != 1)
	{
	    SetLastError(0);
	    return(0);
	}
    for(i = 0; i < npfd;i++)
	{
	    delta = 0;
	    if(
		(ppfd->dwFlags & PFD_DRAW_TO_WINDOW) &&
		!(pfd[i].pfd.dwFlags & PFD_DRAW_TO_WINDOW))
		continue;
	    if(
		(ppfd->dwFlags & PFD_DRAW_TO_BITMAP) &&
		!(pfd[i].pfd.dwFlags & PFD_DRAW_TO_BITMAP))
		continue;
	    if(
		(ppfd->dwFlags & PFD_SUPPORT_GDI) &&
		!(pfd[i].pfd.dwFlags & PFD_SUPPORT_GDI))
		continue;
	    if(
		(ppfd->dwFlags & PFD_SUPPORT_OPENGL) &&
		!(pfd[i].pfd.dwFlags & PFD_SUPPORT_OPENGL))
		continue;
	    if(
		!(ppfd->dwFlags & PFD_DOUBLEBUFFER_DONTCARE) &&
		((ppfd->dwFlags & PFD_DOUBLEBUFFER) != 
		 (pfd[i].pfd.dwFlags & PFD_DOUBLEBUFFER)))
		continue;
	    if(
		!(ppfd->dwFlags & PFD_STEREO_DONTCARE) &&
		((ppfd->dwFlags & PFD_STEREO) != 
		 (pfd[i].pfd.dwFlags & PFD_STEREO)))
		continue;
	    if(ppfd->iPixelType != pfd[i].pfd.iPixelType)
		delta++;
	    if(ppfd->cAlphaBits != pfd[i].pfd.cAlphaBits)
		delta++;
	    if(delta < bestdelta)
		{
		    best = i + 1;
		    bestdelta = delta;
		    if(bestdelta == 0)
			break;
		}
	}
    if(best == -1)
	{
	    SetLastError(0);
	    return(0);
	}
    return(best);
}

WINGDIAPI int GLAPIENTRY wglDescribePixelFormat(HDC hdc,
					        int iPixelFormat,
					        UINT nBytes,
					        LPPIXELFORMATDESCRIPTOR ppfd)
{
    (void) hdc;
    
    if(ppfd == NULL)
	return(npfd);
    if(iPixelFormat < 1 || iPixelFormat > npfd || 
       nBytes != sizeof(PIXELFORMATDESCRIPTOR))
	{
	    SetLastError(0);
	    return(0);
	}
    *ppfd = pfd[iPixelFormat - 1].pfd;
    return(npfd);
}

WINGDIAPI PROC GLAPIENTRY wglGetProcAddress(LPCSTR lpszProc)
{
    PROC p = (PROC) _glapi_get_proc_address((const char *) lpszProc);
    if (p)
	return p;
    
    SetLastError(0);
    return(NULL);
}

WINGDIAPI int GLAPIENTRY wglGetPixelFormat(HDC hdc)
{
    (void) hdc;
    if(curPFD == 0) {
	SetLastError(0);
	return(0);
    }
    return(curPFD);
}

WINGDIAPI BOOL GLAPIENTRY wglSetPixelFormat(HDC hdc,int iPixelFormat,
					const PIXELFORMATDESCRIPTOR *ppfd)
{
    (void) hdc;
    
    if(iPixelFormat < 1 || iPixelFormat > npfd || 
       ppfd->nSize != sizeof(PIXELFORMATDESCRIPTOR)) {
	SetLastError(0);
	return(FALSE);
    }
    curPFD = iPixelFormat;
    return(TRUE);
}

WINGDIAPI BOOL GLAPIENTRY wglSwapBuffers(HDC hdc)
{
    WMesaSwapBuffers(hdc);
    return TRUE;
}

static FIXED FixedFromDouble(double d)
{
   long l = (long) (d * 65536L);
   return *(FIXED *) (void *) &l;
}


/*
** This is cribbed from FX/fxwgl.c, and seems to implement support
** for bitmap fonts where the wglUseFontBitmapsA() code implements
** support for outline fonts.  In combination they hopefully give
** fairly generic support for fonts.
*/
static BOOL wglUseFontBitmaps_FX(HDC fontDevice, DWORD firstChar,
                                 DWORD numChars, DWORD listBase)
{
#define VERIFY(a) (void)(a)
    
    TEXTMETRIC metric;
    BITMAPINFO *dibInfo;
    HDC bitDevice;
    COLORREF tempColor;
    int i;
    
    VERIFY(GetTextMetrics(fontDevice, &metric));
    
    dibInfo = (BITMAPINFO *) calloc(sizeof(BITMAPINFO) + sizeof(RGBQUAD), 1);
    dibInfo->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
    dibInfo->bmiHeader.biPlanes = 1;
    dibInfo->bmiHeader.biBitCount = 1;
    dibInfo->bmiHeader.biCompression = BI_RGB;
    
    bitDevice = CreateCompatibleDC(fontDevice);
    
    /* Swap fore and back colors so the bitmap has the right polarity */
    tempColor = GetBkColor(bitDevice);
    SetBkColor(bitDevice, GetTextColor(bitDevice));
    SetTextColor(bitDevice, tempColor);
    
    /* Place chars based on base line */
    VERIFY(SetTextAlign(bitDevice, TA_BASELINE) != GDI_ERROR ? 1 : 0);
    
    for(i = 0; i < (int)numChars; i++) {
	SIZE size;
	char curChar;
	int charWidth,charHeight,bmapWidth,bmapHeight,numBytes,res;
	HBITMAP bitObject;
	HGDIOBJ origBmap;
	unsigned char *bmap;
	
	curChar = (char)(i + firstChar);
	
	/* Find how high/wide this character is */
	VERIFY(GetTextExtentPoint32(bitDevice, &curChar, 1, &size));
	
	/* Create the output bitmap */
	charWidth = size.cx;
	charHeight = size.cy;
	/* Round up to the next multiple of 32 bits */
	bmapWidth = ((charWidth + 31) / 32) * 32;   
	bmapHeight = charHeight;
	bitObject = CreateCompatibleBitmap(bitDevice,
					   bmapWidth,
					   bmapHeight);
	/* VERIFY(bitObject); */
	
	/* Assign the output bitmap to the device */
	origBmap = SelectObject(bitDevice, bitObject);
	(void) VERIFY(origBmap);
	
	VERIFY( PatBlt( bitDevice, 0, 0, bmapWidth, bmapHeight,BLACKNESS ) );
	
	/* Use our source font on the device */
	VERIFY(SelectObject(bitDevice, GetCurrentObject(fontDevice,OBJ_FONT)));
	
	/* Draw the character */
	VERIFY(TextOut(bitDevice, 0, metric.tmAscent, &curChar, 1));
	
	/* Unselect our bmap object */
	VERIFY(SelectObject(bitDevice, origBmap));
	
	/* Convert the display dependant representation to a 1 bit deep DIB */
	numBytes = (bmapWidth * bmapHeight) / 8;
	bmap = malloc(numBytes);
	dibInfo->bmiHeader.biWidth = bmapWidth;
	dibInfo->bmiHeader.biHeight = bmapHeight;
	res = GetDIBits(bitDevice, bitObject, 0, bmapHeight, bmap,
			dibInfo,
			DIB_RGB_COLORS);
	/* VERIFY(res); */
	
	/* Create the GL object */
	glNewList(i + listBase, GL_COMPILE);
	glBitmap(bmapWidth, bmapHeight, 0.0, (GLfloat)metric.tmDescent,
		 (GLfloat)charWidth, 0.0,
		 bmap);
	glEndList();
	/* CheckGL(); */
	
	/* Destroy the bmap object */
	DeleteObject(bitObject);
	
	/* Deallocate the bitmap data */
	free(bmap);
    }
    
    /* Destroy the DC */
    VERIFY(DeleteDC(bitDevice));
    
    free(dibInfo);
    
    return TRUE;
#undef VERIFY
}

WINGDIAPI BOOL GLAPIENTRY wglUseFontBitmapsA(HDC hdc, DWORD first,
					     DWORD count, DWORD listBase)
{
    int i;
    GLuint font_list;
    DWORD size;
    GLYPHMETRICS gm;
    HANDLE hBits;
    LPSTR lpBits;
    MAT2 mat;
    int  success = TRUE;
    
    if (count == 0)
	return FALSE;
    
    font_list = listBase;
    
    mat.eM11 = FixedFromDouble(1);
    mat.eM12 = FixedFromDouble(0);
    mat.eM21 = FixedFromDouble(0);
    mat.eM22 = FixedFromDouble(-1);
    
    memset(&gm,0,sizeof(gm));
    
    /*
    ** If we can't get the glyph outline, it may be because this is a fixed
    ** font.  Try processing it that way.
    */
    if( GetGlyphOutline(hdc, first, GGO_BITMAP, &gm, 0, NULL, &mat)
	== GDI_ERROR ) {
	return wglUseFontBitmaps_FX( hdc, first, count, listBase );
    }
    
    /*
    ** Otherwise process all desired characters.
    */
    for (i = 0; i < (int)count; i++) {
	DWORD err;
	
	glNewList( font_list+i, GL_COMPILE );
	
	/* allocate space for the bitmap/outline */
	size = GetGlyphOutline(hdc, first + i, GGO_BITMAP, 
			       &gm, 0, NULL, &mat);
	if (size == GDI_ERROR) {
	    glEndList( );
	    err = GetLastError();
	    success = FALSE;
	    continue;
	}
	
	hBits  = GlobalAlloc(GHND, size+1);
	lpBits = GlobalLock(hBits);
	
	err = 
	    GetGlyphOutline(hdc,         /* handle to device context */
			    first + i,   /* character to query */
			    GGO_BITMAP,  /* format of data to return */
			    &gm,         /* ptr to structure for metrics*/
			    size,        /* size of buffer for data */
			    lpBits,      /* pointer to buffer for data */
			    &mat         /* pointer to transformation */
			    /* matrix structure */
		);
	
	if (err == GDI_ERROR) {
	    GlobalUnlock(hBits);
	    GlobalFree(hBits);
	    
	    glEndList( );
	    err = GetLastError();
	    success = FALSE;
	    continue;
	}
	
	glBitmap(gm.gmBlackBoxX,gm.gmBlackBoxY,
		 (GLfloat)-gm.gmptGlyphOrigin.x,
		 (GLfloat)gm.gmptGlyphOrigin.y,
		 (GLfloat)gm.gmCellIncX,
		 (GLfloat)gm.gmCellIncY,
		 (const GLubyte * )lpBits);
	
	GlobalUnlock(hBits);
	GlobalFree(hBits);
	
	glEndList( );
    }
    
    return success;
}

WINGDIAPI BOOL GLAPIENTRY wglShareLists(HGLRC hglrc1,
					HGLRC hglrc2)
{
    WMesaShareLists((WMesaContext)hglrc1, (WMesaContext)hglrc2);
    return(TRUE);
}



/* NOT IMPLEMENTED YET */
WINGDIAPI BOOL GLAPIENTRY wglCopyContext(HGLRC hglrcSrc,
					 HGLRC hglrcDst,
					 UINT mask)
{
    (void) hglrcSrc; (void) hglrcDst; (void) mask;
    return(FALSE);
}

WINGDIAPI HGLRC GLAPIENTRY wglCreateLayerContext(HDC hdc,
						 int iLayerPlane)
{
    SetLastError(0);
    if (iLayerPlane == 0)
        return wglCreateContext( hdc );
    return(NULL);
}


WINGDIAPI BOOL GLAPIENTRY wglUseFontBitmapsW(HDC hdc,
					     DWORD first,
					     DWORD count,
					     DWORD listBase)
{
    (void) hdc; (void) first; (void) count; (void) listBase;
    return FALSE;
}

WINGDIAPI BOOL GLAPIENTRY wglUseFontOutlinesA(HDC hdc,
					      DWORD first,
					      DWORD count,
					      DWORD listBase,
					      FLOAT deviation,
					      FLOAT extrusion,
					      int format,
					      LPGLYPHMETRICSFLOAT lpgmf)
{
    (void) hdc; (void) first; (void) count;
    (void) listBase; (void) deviation; (void) extrusion; (void) format;
    (void) lpgmf;
    SetLastError(0);
    return(FALSE);
}

WINGDIAPI BOOL GLAPIENTRY wglUseFontOutlinesW(HDC hdc,
					      DWORD first,
					      DWORD count,
					      DWORD listBase,
					      FLOAT deviation,
					      FLOAT extrusion,
					      int format,
					      LPGLYPHMETRICSFLOAT lpgmf)
{
    (void) hdc; (void) first; (void) count;
    (void) listBase; (void) deviation; (void) extrusion; (void) format;
    (void) lpgmf;
    SetLastError(0);
    return(FALSE);
}

WINGDIAPI BOOL GLAPIENTRY wglDescribeLayerPlane(HDC hdc,
						int iPixelFormat,
						int iLayerPlane,
						UINT nBytes,
						LPLAYERPLANEDESCRIPTOR plpd)
{
    (void) hdc; (void) iPixelFormat; (void) iLayerPlane; 
    (void) nBytes; (void) plpd;
    SetLastError(0);
    return(FALSE);
}

WINGDIAPI int GLAPIENTRY wglSetLayerPaletteEntries(HDC hdc,
						   int iLayerPlane,
						   int iStart,
						   int cEntries,
						   CONST COLORREF *pcr)
{
    (void) hdc; (void) iLayerPlane; (void) iStart; 
    (void) cEntries; (void) pcr;
    SetLastError(0);
    return(0);
}

WINGDIAPI int GLAPIENTRY wglGetLayerPaletteEntries(HDC hdc,
						   int iLayerPlane,
						   int iStart,
						   int cEntries,
						   COLORREF *pcr)
{
    (void) hdc; (void) iLayerPlane; (void) iStart; (void) cEntries; (void) pcr;
    SetLastError(0);
    return(0);
}

WINGDIAPI BOOL GLAPIENTRY wglRealizeLayerPalette(HDC hdc,
						 int iLayerPlane,
						 BOOL bRealize)
{
    (void) hdc; (void) iLayerPlane; (void) bRealize;
    SetLastError(0);
    return(FALSE);
}

WINGDIAPI BOOL GLAPIENTRY wglSwapLayerBuffers(HDC hdc,
					      UINT fuPlanes)
{
    (void) hdc; (void) fuPlanes;
    SetLastError(0);
    return(FALSE);
}

WINGDIAPI const char * GLAPIENTRY wglGetExtensionsStringARB(HDC hdc)
{
    return "WGL_ARB_extensions_string";
}